Sintering and Electronic Conducting Properties of Lao.7Ca0.3CrO3 Perovskite Synthesized by a Glycine-nitrate Process

La0.7 Ca0.3 CrO3 powder consisting of superfine and uniform particles （ 100-200 nm ） were synthesized using a glycine-nitrate process （ GNP ）. The sintering and electronic conducting properties of La0.7 Ca0.3 CrO3 were invetigated in the sintering temperature range of 1 200-1 450 ℃. The desired morphology of the powder significantly improved its sinterability. La0.7 Ca0.3 CrO3 ceramics sintered at 1 250-1 450 ℃ show high relative densities above 95 % . The ceramics sintered at 1 250-1 400 ℃ have very similar electronic conduct- ing properties, providing electronic conductivities around 55 Ω^-1 cm^-1 at a measuring temperature of 800 ℃ . Further increasing the sintering temperature to 1450 ℃ led to an apparent degradation of electronic conducting properties. This research demonstrates the advantage of the GNP in producing La0.7 Ca0.3 CrO3 with respect to the enhanced sintering properties and superior electronic conducting properties.     

Optical field concentration in low-index waveguides

We present a highly efficient optical field concentrator that is capable of confining optical field in nanometer-thin low-index media with very high optical confinement factor. The structure is made of multiple-layered low-index nanolayers embedded in high-index silicon waveguides. By creating multiple high-index-contrast interfaces, the normal field in the low-index nanolayer regions is significantly enhanced. It subsequently results in a very high optical confinement and power density in these regions. With the help of numerical simulation tools, the guiding and propagating characteristics of the new structure are studied and presented. The optimal structures have demonstrated confinement factors and normalized power densities in the range of 30%-60% and 20-160 /spl mu/m/sup -2/ for the 5-20-nm thin low-index multiple nanolayers.     

The transistor laser

A research team at the University of Illinois at Urbana-Champaign has developed a new, more powerful kind of device, called the transistor laser. The transistor puts out both electrical signals and a laser beam, which can be directly modulated to send optical signals at the rate of 10 billion bits per second. With some further modification, the transistor laser will eventually send a staggering 100 billion bits per second or more. Instead of using relatively slow wires to connect chips stacked together in packages, transistor lasers can be used as optical interconnects, which would let data flow instantaneously to and from memory chips, graphics processors, and microprocessors. There is much work ahead, but unlike the host of self-assembling, blue-sky nanotechnologies currently being touted as the next big thing in optoelectronics, transistor lasers do not need an entirely new fabrication infrastructure for further development or even to go into production.     

荧光定量PCR仪实时控制与数据采集的后台实现

通过对荧光定量PCR仪硬件系统结构的分析,提出一种基于LabVIEW Ⅵ server技术的方法.该方法可以对PCR反应控制、数据采集两个独立的单片机系统进行实时监控,实现了前台数据实时显示、后台实时监控的功能.     

Electroplated hard magnetic material and its application in microelectromechanical systems

We describe the preparation of CoNiMnP-based permanent-magnet material using several sulfate and chloride solutions. We studied eight samples, and all the samples show vertical magnetic anisotropy. Sample8, which was electroplated from a low-concentration chloride solution and under external magnetic field, demonstrates the best magnetic properties with coercivity 2632 Oe, remanence 0.20 T, and maximum magnetic energy 10.185 kJ/m/sup 3/. An array structure can avoid the stress between the electroplated layer and the seed layer. The electroplated Co/sub 0.8/Ni/sub 0.1174/Mn/sub 0.0062/P/sub 0.0762/ permanent magnet has potential for bidirectional actuators in micro-electromechanical systems.     

材料韧性断裂的细观力学分析与测试

应用细观力学的观点分析材料韧性断裂方面的独到之处及便利，并结合高强铸铁细观力学的断裂判据——临界空穴扩张比的测试研究，介绍了作者在应用细观力学研究高强铸铁韧性断裂方面所做的工作及进展     

衍射图像的信号采集和数据处理

针对衍射图像边缘弥散状态不易切准的问题，运用光电积分的方法确定采集点，然后将二值化的数据通过计算机采用最小二乘法进行计算，从而保证了测量结果的正确性     

浅谈柔性制造系统的现状及实施

本文以美国所用柔性制造系统为例，以大量翔实的数据。阐述了柔性制造系统使用的现状及存在的问题，并针对这些问题提出相应的措施。     

变压器隔离方式的安全栅

论文介绍爆炸产生原因,综合比较自动化仪表各种防爆方法,介绍了最切实有效,最安全可靠的本质安全防爆方法,以本质安全防爆的原理为基础,设计利用隔离变压器来实现安全区和危险区隔离的一种新型的无源隔离式安全栅.